Fuze-testing apparatus



April 3o, 196s Filed Dec. 5,

WALTER N. STEWART @Howe/ua United States Patent O 3,380,297 FUZE-TESTING APPARATUS Walter N. Stewart, Willingboro, NJ., assignor to the United States of America as represented by the Secretary of the Army Filed Dec. 3, 1965, Ser. No. 511,570 6 Claims. (Cl. 73-167) ABSTRACT F THE DISCLOSURE A device for testing point detonating fuzes connisting of a tube having a spring retractable plunger yat the bottom which detonates the fuze when an octagonal shaped striker is dropped thereon through the tube.

The invention described herein may be manufactured and used by or for the lGovernment for governmental purposes Without the payment to me of any royalty thereon.

The invention relates to a fuze-testing apparatus and more particularly to a fuze-testing apparatus for point detonating fuzes.

In the past, point detonating fuzes have been tested by using a device which included a motor having :a spindle on which was mounted a fuze having Ia point detonating element in the nose thereof. A drop tube was held in place by the operator, directly above the fuze, `and while the fuze was rotating, a plunger was dropped by the opertor into the drop tube and thereby onto the point detonating element. As :a result of this hand operation, the plunger could jam in the nose of the fuze and rotate with the fuze, causing =a hazard to the operator and possible damage to the test equipment. It was also necessary, after each test, to remove the plunger which had remained in the fuze.

It is therefore an object of the invention to provide a fuze testing apparatus that is safe to operate.

Another object is the provision of a fuze-testing apparatus that cannot cause damage to the fuze being tested.

Still another object is to provide a fuze testing apparatus that will alleviate the necessity to remove the plunger after each test.

The above objects `as well as others together with the benets and advantages of the invention will be lapparent upon reference to the detailed description set forth below, particularly when taken in conjunction with the drawing annexed hereto.

As seen in the drawing a point detonating fuze testing apparatus 10 consists of two main components, namely a detonating -assembly 12 and an explosion chamber 14. The detonating assembly 12 includes a slide tube 16, and a plunger assembly 18. Plunger assembly 18 includes a block 2t) having a rst axial cavity 22 extending part way through the block 20 and a second axial cavity 24 of lesser diameter extending the rest of the way through the block 20 beginning at the base of the cavity 22. A plunger 26, having a tapered portion 28, is adapted to fit into both the cavities 22 and 24. Integral with plunger 26 is a bar 27 which is form tted within the cavity 22. The bar 27 abuts a tapered washer 30 which is integral with -a drop tube 32 by way of pipe threads 34. A return coil spring 36 is mounted at 38 to the block 20 and at 40 to the bar 27 so as to provide the pressure necessary to return the plunger 26 to the inoperative position as seen in the draw- 3,380,297 Patented Apr. 30, 1968 ICC ing. The block 20 isy slidable in slide tube 16 -so as to bc adjustable `as to height to accommodate any size fuze and can be locked into position by utilizing the two lock screws 42 .and 44.

IExplosion chamber 14, includes an upright steel encased housing 46 of suicient strength to contain the explosion of the point detonating fuze. The housing 46 is secured to a support frame 48 by welding or the like. The housing 46 contains a spindle 50 upon which is seated the point detonating fuze '52 to be tested. The plunger 26 is coaxial with the center point of the spindle 50 which is'seated on a vertical shaft 54. A variable speed motor 56 is ixedly mounted to the outside surface ofthe housing 46. The motor 56 is of the type described in Patent Application Serial No. 436,968 tiled March 3, 1965, now Patent No. 3,329,014. The rotor 58 of the motor 56 has an integrally mounted pulley 60 which is co-planar with another pulley 62 iixedly mounted on shaft 54. The pulley 60 .and 62 are interconnected to each other by a belt 64 suited for this purpose. By the above arrangement of elements it can `readily be seen that the motor 56 and spindle 50 lare operatively connected so that the motor 56 may drive the spindle 50 to -a pre-selected speed. The motor 56 is connected to a suitable electrical power source (not shown).

In operation, after the fuze 52 is splaced on the spindle 50, the motor '56 is turned on, thereby causing the fuze 52 to revolve at a pre-determined speed. Once the fuze is spinning, arming takes place in ya known manner, and an octagonal shaped striker 66 is released into the drop tube 32. The shape of the striker 66 .allows it to move down the drop tube 32 at a velocity necessary to cause the plunger 26 and its tapered portion 28 to enter the nose of the fuze 52 which sets off a point detonating element (not shown) and then because of the action of the coil spring 36 to return to the inoperative position.

Obviously many modiiications land variations of the present invention are possible in the light of the above teachings. It is therefore to be understood, that within the scope of the -appended claims, the invention may be practised otherwise than as specically described.

I claim:

1. A fuze testing apparatus having an explosion chamber .and a detonating assembly, said detonating assembly a including a slide tube, a plunger assembly adjustably secured in said slide tube and including a block having a first axial cavity extending partway therethrough an ending in a base portion, and `a second axial cavity extending through said base portion and the remaining portion of said block,

a drop tube having a tapered end portion secured partially in said first .axial cavity,

a plunger resiliently secured in the remaining portion of said first axial cavity and having a tapered portion extending into said second Iaxial cavity,

resilient means in said 4block for automatically causing immediate withdrawal of said plunger out of said explosion chamber after detonation,

a striker so constructed and arranged to be to move downwardly into said explosion chamber and detonate a fuze secured `therein tov be tested.

2. An apparatus `of the type described in `claim 1 wherein said resilient means includes a coil spring seated on said base portion of said block.

3. An apparatus of the type described in claim 1 wherein said plunger has a bar which abuis the tapered end portion of the drop tube, said bar being integral with said plunger.

4. An apparatus of the type described in claim 3 wherein said plunger assembly is adjustably secured to said slide tube by a plurality of lock screws.

References Cited UNITED STATES PATENTS 1,801,449 4/1931 Olsen et al. 73-35 2,966,791 1/1961 Ivins 73-12 10 3,329,014 7/1967 Stew-art 73--167 DAVID SCHONBERG, Primary Examiner. 

